1. Field of the Invention
This invention relates to a three-dimensional information handling system in computer graphics.
2. Description of the Prior Art
In the field of computer graphics, there are various techniques of stereographically indicating three-dimensional graphics information on a two-dimensional screen such as the screen of a CRT. In general, a three-dimensional cursor is used in designating a point within an indicated three-dimensional space and in selecting one of indicated three-dimensional figures (objects). In some cases, it is difficult to understand the positional relation between a three-dimensional cursor and a three-dimensional object on a screen. In addition, selecting one of three-dimensional objects by using a cursor tends to be troublesome.
U.S. Pat. No. 4,812,829 discloses a three-dimensional display device which includes a display, an input section, and a controller. The display indicates a three-dimensional image, a vector cursor, and a pointing image (pointer) extending in a direction of movement of the vector cursor. The controller generates a display signal to execute the indication of the three-dimensional image, the vector cursor, and the pointing image. The controller recognizes the three-dimensional image crossing to the pointing image in response to the pointing signal form the input section.
U.S. Pat. No. 4,808,979 relates to a cursor for use in a three-dimensional imaging system. The cursor includes a reference symbol, a tether symbol, and a pointer symbol.
U.S. Pat. No. 4,835,528 discloses a cursor control system in which hairs passing through a cursor assist the user in unambiguously locating the cursor within a three-dimensional object.